private void getChildren(boolean setStringMoves) {
dbh.getCharArray(oldPosition);
int counter = 0;
// looks at every spot on the board
for (int row = 0; row < height; row++) {
for (int col = 0; col < width; col++) {
// only a valid child if there is an empty space there
if (board[row][col].getPiece() == ' ') {
Cell place = board[row][col];
Cell[] neighbors = place.getNeighbors();
// looks at each spot around the given spot
for (int index = 0; index < 8; index++) {
// makes sure the spot is within bounds, then checks if
// there is an opposing piece next to it
Cell neighbor = neighbors[index];
if (neighbor != null
&& neighbor.getPiece() == pieces[opposite(turn)]
&& isFlippable(place.boardNum, index, false, null)) {
if (setStringMoves) {
stringMoves[counter] = (char) (col + 'A') + Integer.toString(row + 1);
}
System.arraycopy(oldPosition, 0, tempPosition, 0, boardSize);
isFlippable(place.boardNum, index, true, tempPosition);
int newWhitePieces = count(tempPosition);
int nextTier = getTier() + 1;
children[counter].tier = nextTier;
children[counter].hash =
offsetTable[nextTier][opposite(turn)][newWhitePieces]
+ dbh.setNumsAndHash(tempPosition);
counter++;
dbh.setNumsAndHash(oldPosition);
break;
}
}
}
}
}
if (setStringMoves && counter == 0) {
turn = opposite(turn);
getChildren(false);
if (numChildren > 0) {
stringMoves[0] = "pass";
children[0].tier = getTier();
children[0].hash = getHash();
counter = 1;
}
turn = opposite(turn);
}
numChildren = counter;
isChildrenValid = true;
}
private boolean isFlippable(int boardNumber, int direction, boolean flip, char[] tempPosition) {
int addRow = 0;
int addCol = 0;
switch (direction) {
case 0:
addRow = -1;
addCol = -1;
break;
case 1:
addRow = -1;
addCol = 0;
break;
case 2:
addRow = -1;
addCol = 1;
break;
case 3:
addRow = 0;
addCol = -1;
break;
case 4:
addRow = 0;
addCol = 1;
break;
case 5:
addRow = 1;
addCol = -1;
break;
case 6:
addRow = 1;
addCol = 0;
break;
case 7:
addRow = 1;
addCol = 1;
break;
default:
throw new Error("Bad direction");
}
int row = boardNumber / width;
int col = boardNumber % height;
if (flip) {
tempPosition[row * width + col] = (turn == BLACK ? 'X' : 'O');
}
char piece = 'P';
row += addRow;
col += addCol;
int pieceCounter = 0;
while (col >= 0 && col < width && row >= 0 && row < height) {
piece = (flip ? tempPosition[row * width + col] : board[row][col].getPiece());
if (piece == ' ' || (pieceCounter == 0 && piece == (turn == BLACK ? 'X' : 'O'))) break;
else {
if (flip) tempPosition[row * width + col] = pieces[turn];
if (pieceCounter > 0 && piece == (turn == BLACK ? 'X' : 'O')) {
if (flip) {
for (int direct = 0; direct < 8; direct++) {
if (direct != direction && isFlippable(boardNumber, direct, false, null))
isFlippable(boardNumber, direct, true, tempPosition);
}
}
return true;
}
row += addRow;
col += addCol;
if (piece == (turn == BLACK ? 'O' : 'X')) pieceCounter++;
}
}
return false;
}